The present invention relates to olefin polymerization with catalysts derived from chromium exchanged zeolites.
The supports commonly used for transition metal ethylene polymerization catalysts of the Phillips type have generally been high surface area amorphous silicas or silica-aluminas. These have been impregnated with chromium salts, calcined, and reduced to produce the low valency transition metal stabilized by reaction with the silica hydroxyls required for an active polymerization catalyst.